A sharpening stone is a stone that has got a coarse side and usually a finer side, and that is going to take and re-shape your edge and get it back down thin enough in order to sharpen it. You are basically taking something that is blunt and thinning it back down. You have to remove all of this extra metal and get it back down to where it is thin enough to cut. Very simply, all a knife is is a very thin piece of steel to split whatever you are cutting. If the knife is obviously thicker, it is like trying to cut something with a chisel; it is not going to happen.
Ceramic whetstones are meant to be used without water or oil, which means they can be used almost anywhere and are ideal for chefs or cooks who have limited working spaces. They will give you a very sharp blade and as their surface is very hard they will maintain their flat surfaces over the long-term, but as they have a fine grit, they can break if you drop the stone.

To use Al's method, take a black felt pen and shade in the bevel of the knife. Then take two strokes on the stone and examine the edge. If you have maintained the proper angle then all the black will be gone. If you see black on the top of the edge it means you are holding the back of the knife too far from the stone. If there is black on the bottom of the edge but the top is clean then you are laying the knife too flat on the stone and you need to raise it a bit. Repaint the edge and try it again. Once you discover what the right angle looks like then just maintain that.

4 double-sided whetstones with 8 different grits to get your knives and tools sharper than ever. This kit includes everything that you could need to start sharpening at home right now. These premium quality whetstones require no oil, and come with a flattening stone, a blade angle guide, a no slip bamboo sharpening base, and now a free form fit storage and carrying case.
Modern synthetic stones are generally of equal quality to natural stones, and are often considered superior in sharpening performance due to consistency of particle size and control over the properties of the stones. For example, the proportional content of abrasive particles as opposed to base or "binder" materials can be controlled to make the stone cut faster or slower, as desired.[7] Natural stones are often prized for their natural beauty as stones and their rarity, adding value as collectors' items. Furthermore, each natural stone is different, and there are rare natural stones that contain abrasive particles in grit sizes finer than are currently available in artificial stones.[citation needed]
You've acquired a good chef's knife, you're using it almost daily to make tasty dinners for the family, and it's stored in a nice knife rack or a magnet for safekeeping. So why stop there? Keeping that knife's edge fine will make cooking not only safer but, let's face it, much more fun. Whether you've spent £150 on a high-end knife or under a tenner on a dinky paring knife, keeping it sharp is crucial. 

You will also need at least one finer stone. Once the shape of an edge is established, successively finer grits are used to refine the edge improving the quality of the cut it delivers. A dull edge will not cut well and should be shaped with a coarse stone. An edge sharpened on a coarse stone will cut better than a dull one, but still won’t be ideal and should be improved with a finer stone. As you progress through finer stones, the cutting edge will continue to improve. How many and how fine these stones need to be varies depending on how fine an edge you require.
We used the honing rods on multiple knives, including our top pick for chef’s knives, the 8-inch Mac MTH-80—a hard Japanese blade—and a vintage 12-inch Wüsthof, a German knife with a softer blade. That covers the two main types of knives that people commonly own. To dull the knives between tests, we repeatedly sawed through 1-inch-thick hemp rope, a classic challenge used by knifemakers to demonstrate their blades’ durability. We focused on 12-inch rods, because a longer rod is easier to use—it offers more room to sweep the length of a standard 8- or 10-inch chef’s knife.
A great sharpener for all your kitchen knives the CS2 also makes a smart addition to the gear when you’re going away on a family camping trip. It will also do a bang-up job on your hunting, pocket, boning knife and more. As mentioned it does require just a bit of getting used to in order to achieve optimal results but nothing too involved. A simple, effective, no-frills sharpener.
Technically, the name whetstone can be applied to any form of sharpening stone, regardless of what cutting fluid is typically used with it. However because whet sounds like wet, many hear the word and assume that it refers to a stone that is used wet with water. Actually, water stones, oil stones diamond stones and ceramic stones are all forms of whetstones. So, while all water stones are whetstones, not all whetstones are water stones.

Our test targets consisted of 5 pounds of tomatoes and sheets of regular 8½-by-11-inch paper from a writing pad. (The “paper cut” test is a universal standard among sharpening enthusiasts.) After we tested each knife against both objects in its dull state, we sharpened it according to the manufacturer’s instructions on one of the seven sharpeners. We then repeated the tests and noted the relative improvements in cutting performance. We also paid attention to an issue that’s common to virtually all manual and electric sharpeners: their inability to sharpen all the way to the heel of the blade, the part closest to the handle. While stones and jigs can sharpen the entire length of a blade, most manual and electric sharpeners have a slotlike structure around the sharpening element that prevents the last quarter-inch (best case) to inch (worst) of the edge from reaching the sharpening element.

Actually, the company contacted me to make sure I received the stones and that I was happy with them. Excellent service. The stones are great! I'm pretty much a novice so the clear instructions that came with the stones and the eBook instructions were wonderful. The eBook had quality pictures demonstrating the use of the stones and the written instructions were clear and to the point. Within minutes of opening the box I had the stones figured out and sharpening my AF survival knife, my pocket knife and a couple of my wife's kitchen knives...which included a very expensive chef's knife. Very satisfied with this product and highly recommend it.

We tend to recommend natural Japanese water stones only to experienced users who are thoroughly familiar with the synthetic Japanese sharpening stones. Natural stones are not to everybody’s taste and there are inevitably many uncertainties with regard to their grit grade, which cannot be determined exactly, their hardness and their suitability for certain types of steel.
Aluminum-Oxide oil stones are very popular man-made sharpening stones produced by an abrasives company called Norton and which are commonly called India Stones. Generally less expensive than Arkansas stones (aka Novaculite), these stones are graded coarse, medium, and fine and are designed for fast cutting. Yet, when the fine grit is used, they can also produce a relatively fine edge. Also, because India Oil Stones are both softer and coarser than Arkansas Stones, they are commonly used in conjunction with Novaculite to cut the initial edge bevels or, repair extremely dull or damaged edges before refining and polishing the bevel with an Arkansas Stone.